1. Field of the Invention
The present invention relates to an equipment direct-mounting-type shield electric connector.
The present application is based on Japanese Patent Application No. Hei. 11-316662, which is incorporated herein by reference.
2. Description of the Related Art
There has heretofore been proposed a shield-type electric connector as shown in FIG. 7.
This shield-type electric connector 80 comprises a first shield connector 82 (see, for example, Unexamined Japanese Patent Publication Nos. Hei. 8-78098 and Hei. 8-64306), mounted directly on an equipment (electrical equipment) 81, and a second shield connector 83 (see, for example, Unexamined Japanese Patent Publication Nos. Hei. 7-245153 and Hei. 7-282891) connected to the first shield connector 82.
The first shield connector 82 comprises a first connector housing 84 of a synthetic resin, mounted directly on the equipment 81, and a first metal terminal 85 inserted in the first connector housing 84. The first connector housing 84 has a hood portion 86 for receiving a second (mating) connector housing 90, and a metal terminal receiving chamber 87 for receiving the first metal terminal 85 is formed within the hood portion 86, and extends therethrough. An engagement hole 86a is formed through an outer wall of the hood portion 86. An outer peripheral surface of the metal terminal receiving chamber 87 is covered with a first shielding shell 88 made of metal. The first shielding shell 88 is connected to an electrically-conductive contact member 89 provided between the first connector housing 84 and a wall surface 81a of the equipment 81.
The second shield connector 83 comprises the second connector housing 90, made of a synthetic resin, a second metal terminal 91, inserted in the second connector housing 90, and a second shielding shell 92 of metal mounted in the second connector housing 90. A metal terminal receiving chamber 93 is formed within the second connector housing 90, and a lock projection 94 is formed on and projects from an outer surface of the second connector housing 90. A conductor 95a of a shielded wire (or cable) 95 is electrically connected to the second metal terminal 91. The second metal terminal 91 is inserted in the second shielding shell 92, and a braided wire 95b of the shielded wire 95 is secured to a rear end of the second shielding shell 92. The engagement hole 86a in the first connector housing 84 and the lock projection 94 on the second connector housing 90 jointly provide a lock mechanism.
When the second shield connector 83 is pushed into the first shield connector 82, the second connector housing 90 is inserted into the hood portion 86 of the first connector housing 84. The first metal terminal 85 is electrically connected to the second metal terminal 91, and the first shielding shell 88 is electrically connected to the second shielding shell 92. The lock projection 94 on the second connector housing 90 is engaged in the engagement hole 86a in the first connector housing 84. Namely, the first and second shield connectors 82 and 83 are fitted together. As a result, the external shielded wire 95 is electrically connected to the equipment 81.
However, the second shield connector 83 (including the external shielded wire 95) and the first shield connector 82, mounted directly on the equipment, have many component parts, and therefore there has been encountered a drawback that many electrical contact points are provided when the two shield connectors 82 and 83 are connected together. As a result, the electrical resistance has increased, and the shielding effected has been lowered.
There has been encountered another problem that a pressing force, acting between the first and second shield connectors 82 and 83 during the connecting operation, increases because of an inserting force, acting between the first and second metal terminals 85 and 91, and a frictional resistance force acting between the first and second shielding shells 88 and 92.
And besides, there has been a possibility that the first and second connector housings 84 and 90 are damaged by the pressing force, acting on these housings during the connecting operation, since the two connector housings 84 and 90 are made of an insulative resin. In addition, the lock projection 94 and the engagement hole 86a are formed by resin molding, and therefore there has been encountered a disadvantage that molds (not shown) for forming the connector housings 84 and 90 are complicated in construction.
With the above problems in view, it is an object of the present invention to provide a shield-type electric connector in which the number of component parts is reduced, thereby achieving an enhanced shielding effect, a reduced pressing force during a connecting operation, the prevention of damage to two connector housings during the connecting operation, and a simplified design of molds for resin-molding the two connector housings.
To achieve the above object, according to a first aspect of the present invention, there is provided an equipment direct-mounting-type shield electric connector which includes a pair of first and second shield connectors fittable to each other,
wherein the first shield connector includes:
a first connector housing, mounted directly on a mounting portion of an equipment, and
a first metal terminal which is inserted into a metal terminal receiving chamber in the first connector housing from a connecting side thereof, and is fixed in the chamber; and
wherein the second shield connector includes:
a second connector housing, abutted against the first connector housing,
a second metal terminal, which is inserted into a metal terminal receiving chamber in the second connector housing from that side thereof remote from a connecting side thereof, and is electrically connected to the first metal terminal, and
a rear holder which is inserted into the second connector housing from that side thereof remote from the connecting side thereof so as to prevent rearward withdrawal of the second metal terminal, and covers an outer surface of the second connector housing, and is retained on an outer surface of the first connector housing.
Accordingly, the first and second shield connectors are simpler in construction as compared with the convention construction. The first and second shield connectors are retained and fixed relative to each other by the rear holder which covers the outer surface of the second connector housing, and serves to prevent the rearward withdrawal of the second metal terminal. With this construction, the first and second connector housings are connected together without the use of the related connector""s lock mechanism.
According to a second aspect of the present invention, it is preferable that the first metal terminal is inserted into the metal terminal receiving chamber in the first connector housing from that side thereof remote from the connecting side thereof, and a second rear holder for preventing rearward withdrawal of the first metal terminal is mounted on the first connector housing.
In the second aspect of the present invention, the rear holder for preventing the rearward withdrawal of the first metal terminal is mounted on the first connector housing, and therefore the metal terminal, which is to be inserted into the first connector housing from that side remote from the connecting side, can be used.
According to a third aspect of the present invention, it is preferable that the outer surfaces of the rear holder and the first connector housing are covered with a shielding shell made of metal, and one end of the shielding shell is fixedly secured to the mounting portion made of metal, and the other end of the shielding shell is fixedly connected to a braided wire of a shielded wire connected to the second metal terminal.
In the third aspect of the present invention, the shielding shell, made of metal, covers the outer surfaces of the rear holder and the first connector housing, and the one end of the shielding shell is fixedly secured to the mounting portion on which the first connector housing is directly mounted, and the other end of the shielding shell is fixedly connected to the braided wire of the shielded wire connected to the second metal terminal. Therefore, the braided wire of the shielded wire is connected to the mounting portion through the shielding shell.
According to a fourth aspect of the present invention, it is preferable that the one end of the shielding shell is fixedly secured to the mounting portion, and the shielding shell has a slanting wall formed intermediate the opposite ends thereof, and the slanting wall urges that side of the rear holder, remote from the connecting side thereof, toward the connecting side thereof.
In the fourth aspect of the present invention, the shielding shell has the slanting wall formed intermediate the opposite ends thereof, and therefore after the one end of the shielding shell is fixedly secured to the mounting portion, the slanting wall urges that side of the rear holder, remote from the connecting side thereof, toward the connecting side thereof, so that the connected condition of the first and second connector housings is maintained.